Ion producing mechanism



April 21, 1959 w. BRO-BECK 2,883,541

v ION PRODUCINGMECHANISM (CHARGE CUPS) Filed Feb. 21, 1946 2Sheets-Sheet 1 INVENTOR.

W/LL/AM M. BROBECK WAM April 21, 1959 W. M. BROBECK ION PRODUCINGMECHANISM (CHARGE CUPS) 2 Sheets-Sheet 2 Filed Feb. 21, 1946 INVENTOR.W/LL/A M M BROBEcK BY United States Patent 2,883,541 ION PRODUCINGMECHANISM (CHARGE CUPS) William M. Brobeck, Berkeley, Calif., assignorto the United States of America as represented by the UnitedStatesAtomic Energy Commission Application February2l, 1946,,Serial No.649,402

3 Claims- (Cl. 250-413) The inventionrelates to means. for ionizingmaterial, particularly materialnorm-ally in a solid, pulverulent, orgranular form, and. is particularly concerned with such a mechanism inwhichthe period of operation of the structure is interrupted from timeto time for the renewal of material to be ionized. More especially, theinvention relates-to a calutron of thetype shown in U.S. Patent No.2,709,222, issued May 24, 1955 to Ernest 0. Lawrence. In Figures 3 to 5of the Lawrence application, there is disclosed :a particular form ofcalutronwith which one embodiment of the present invention isparticularly concerned.

In the operation of a calutron mechanism, it was the practice prior tothis invention to provide a block or structure having a chamber thereininto which material to be ionized was introduced prior to each run orcycle of operation of the structure. The charge-containing chambercommunicated with other chambers leading to other portions of theapparatus, so that there was some difficulty in confining the chargematerial to the desired locale within the charge chamber. Customarily,the material utilized was in pulverulent or granular condition, and witha careful control of the size of the granules it was possible to handlethe charge reasonably well; however, the mentioned procedure was notalways convenient and was not sufficiently adaptable to flexible usage.Furthermore, it was observed that the charge material was not alwaysuniformly heated throughout its mass, giving rise to fluctuations in theevolution of vapor or gas for ionization.

In view of the foregoing circumstances, it is therefore an object of myinvention to provide a means for more effectively confining a chargematerial in a calutron.

Another object of my invention is to provide means for facilitating theready cleaning of a calutron ionization mechanism and the restorationthereof to condition for prompt reoperation.

An additional object of my invention is to provide means for moreuniformly distributing the heat to a charge in a calutron.

An additional object of my invention is to provide means for securelyholding in position charge containers in a calutron without seriouslyinterfering with their ready removal when desired.

Other objects, together with the foregoing, will appear from thefollowing description, wherein I have described a preferred form of myinvention. This form of the invention is also illustrated in theaccompanying drawings, in which:

Figure l is a fragmentary view of a calutron mechanism, there beingshown in section a calutron tank having situated therein a calutronsource unit, portions being shown in side elevation and portions beingbroken away to disclose the interior construction of the mechanism.

Fig. 2 is an exploded, isometric view of the charge chamber and itsimmediate environment, some portions being disclosed in cross section toillustrate clearly the interior arrangement of the calutron ionizationor source mechanism.

In order to review briefly the construction of a calutron, disclosed infull in the above-identified Lawrence application, it is pointed outthat a cal-utron is inclusive of an ion source unit, generallydesignated 6, disposed in the evacuated interior 7 of a tank defined bya side wall 8, a top wall 9, and a bottom wall 11. The tank is situatedin a magnetic fieldestablished betweenan upper pole piece 12-and a lowerpole piece 13 of an electromagnet.

The source block 6 is electrically insulatedfrom the tank wall 8 and issupported at the end of a mounting stem 14, extending through anaperture 16 in the wall 8 of the tank and carried by a mounting andadjusting mechanism 17. This latter mechanism forms no part of thepresent invention, and is therefore not described herein in detail. Themechanism 17 is' in turn supported on a framework 18 fastened to anelectrical insulator 19, itself secured to the tank wall 8 by anappropriate fastening mechanism 21.

As more particularly disclosed in Fig. 2, the inner end of the stem 14is connected to the source block 6 by thermal insulators 23, as theblock 6 itself is preferably fabricated of a thermally conductingmaterial such as a metal, for example copper. Within the block 6 isdisposed an electrical heating coil 24, supplied with energy by a lead26 passing through the insulator 19 to an exterior source of energy.Adjacent the heater 24, in thermally conducting relationship therewith,is a gas distribution chamber 27, constituted by a cavity within theblock 6 and having an outlet passage 28 to the interior of the tank 7.

Closing the upper end of the heater cavity 24 and the upper end of thegas distribution cavity 27 is a cover plate 29, secured by fastenings 31and incorporating a support for a pair of filament leads 32 and 33. Theleads extend through the insulator 19 to a source of energy andtennimate in grips 34 and 36 holding a filament 37 over an aperture 38in the plate 29 and in registry with the passage 28. A securing block 41holds the filament leads 32 and 33 in position, while the enclosure ofthe filament is completed by a cap plate 42, removably positioned byfasteners (not shown) operating through cap plate apertures 43.

For supplying the gas distribution chamber 27 with a vapor or gas to besubsequently ionized, the block 6 is provided with a pair of cavities 46and 47, each of cylindrical form and extending almost but not quiteentirely through the metal of the block, so that heat from the source 24is conducted to the walls of each of the cavities 46 and 47. Thecavities communicate with the chamber 27 through outlet apertures 48 and49, respectively, so that gas flow from both chambers 46 and 47 tochamber 27 is readily effected. The two chambers 46 and 47 aresimultaneously closed by a cover plate 51, preferably held removably inposition on the block 6 by fastenings (not shown) operating throughapertures, such as 52, in the top plate 51 and in the block 6.

In especial accordance with my invention, each of the chambers 46 and 47is in part occupied by a charge cup 54 and 55. Each of the cups 54 and55 is a cylindrical receptacle, preferably fabricated of a good thermalconductor, such as metal, and is disposed removably within itsrespective cavity, but preferably with a close thermal contact betweenthe conducting wall of the cup and the defining wall of the chamberholding it. The axial extent of the cup is preferably such that the cupstops just short of the associated outlet aperture 48 or 49. Thematerial of the cups, although thermally conducting, is inert to thecharge contained therein so that despite protracted use, no interactionoccurs. This permits the material of the block 6, if desired, to be madeof material that might itself be affected by the solid or granularcharge.

In order still better to transmit heat to the contained charge, each ofthe cups is provided with a central stem 57, of thermally conductingmaterial eflective to conduct heat from the bottom 58 of the cup intothe central portion of the contained charge. An additional function isperformed by the central stem 57, in that when the cover plate 51 isremoved the stem presents a useful projection for engagement with aremoving tool.

In accordance with this invention, it is possible, after the plate 51 isremoved, to remove the remains of spent charge from a source block 6 andpromptly to introduce new loaded charge cups so that a subsequent runcan quickly be initiated. Furthermore, the heat is uniformly and evenlydistributed to the charge, both from the outside walls and from thecenter stem of the cup. The charge cups in no wise obstruct the outletopenings, although they do confine the charge to the appropriatechambers. Finally, the charge cups are themselves confined by theremovable cover.

What is claimed is:

1 A calutron comprising thermally conducting means forming a chargechamber, a thermally conducting charge holding cup adapted to beremovably disposed within said chamber with the walls of said cup inthermally conducting relationship with said chamber-forming means, and acentral thermally conducting stem incorporated within said cupforconducting heat to the central portion of a charge contained within saidcup.

2. A calutron ion source comprising a source block formed of thermallyconducting material and having a plurality of chambers formed therein,heating means disposed within one of said chambers for supplying heat tosaid source block, and a charge container removably disposed withinanother of said chambers in thermally conducting relationship to saidsource block, said charge container having a heat conducting elementcentrally disposed therein in contact with a wall thereof whereby theinterior of said charge container is uniformly heated.

3. An ion source for a calutron comprising a source block formed of athermally conducting material, a heating chamber within said sourceblock, an electrical heater disposed within said heating chamber andheating said source block, an arc chamber within said source block andcommunicating with the exterior thereof, means establishing an arewithin said are chamber to ionize gas fed therein, a charge chamberwithin said source block communicating with said are chamber, and acharge cup within said charge chamber in contact with the walls thereofand adapted to contain a charge material which is thereby vaporized bythe heat conducted thereto through the charge cup from the source blockto flow in gaseous form into said are chamber to be ionized by the arctherein.

References Cited in the file of this patent UNITED STATES PATENTS

